Drafting apparatus



Nov. 8, 1938. A. LANGsNER 2,136,140

DRAFTING APPARATUS Filed July 25, 1938 2 Sheets-Sheet 1 if) INVENTOR. B ddaja/Wlargarzer A TTORNEY5.

Nov. 8, 1938. A. LANGSNER 5,

DRAFTING APPARATUS Filed July 25, 1938 2 Sheets-Sheet 2 TIFIWIAIIIIIIIIIIIIV iiiiiiiiiiiifli 313 36 J GZJU. 43 41 45 9 INVENTOR.

ddoplwla zganer ATTORNEY 5.

Patented N... s, 1938 UNITED STATES FATE GFFIC Dietzgen Co., Chicago, 11].,

Delaware a corporation of Application July 25, 1938, Serial No. 221,071 8 Claims. (01. 33-49) This invention relates to drafting apparatus, and more particularly to parallel line drafting or ruling apparatus adapted for use on drawing boards or tables.

It is an object of the invention to provide a parallel line ruling or drafting device for use on drafting boards or the like of improved construction and operation, of increased strength and rigidity, and of maintained accuracy.

More specifically it is an object of the invention to provide a parallel line drafting or ruling device of the type having an operating mechanism composed of parallel extending arms or bars, wherein the arms are made of tubular form for increased strength and rigidity and wherein means is provided for adjusting the length of the arms to insure and maintain the parallel and accurate operating relationship between the parts. In accordance with the invention this adjusting means may be of the micrometer or screw thread type to facilitate accuracy of adjustment.

It is a further object of the invention to provide in parallel line or ruling apparatus of the type stated an improved bearing 6r pivot connection for the arms which can be readily adjusted to compensate for wear whereby to maintain accuracy in the apparatus over long periods of use.

A still further object of the invention is to provide in parallel line apparatus a ruling head 80 assembly of improved and simplified construction which can be readily fabricated and assembled readily adjusted to and securely locked in any desired position of angular adjustment, and

.which forms a smooth sliding headconstruction $5 for facilitating ease of movement of the apparatus over the surface of the drawing board.

Still other objects and advantages of the invention willappear from the following descriptione when taken in connection with the accompanying drawings wherein certain preferredembodiments of the invention are set forth for purposes of illustration.

" In the drawings, wherein like reference numerals refer to like parts throughout:

Fig. -1 is an assembly view of a parallel line apparatus constructed in accordance with the principles of .the invention.

Fig. 2 is a detail view, taken along the line 2-2 -of Fig. 1, of the bracket by means of which the apparatus may besecured to a drawing board or thelika: r

Fig. 3 is a detail view of the plate member and associated parts for securing the sets of arms of the operating mechanism together, being taken 55 along the line 3-3 of Fig. 1.

Fig. 4 is a sectional detail of the pivot connection for securing the arms to the plate member, taken along the line 4-4 of Fig. 3.

Fig. 5 is a sectional view through the head construction on the line 5-5 of Fig. 1. 5

Figs. 6 and 7 are detail views of the clamp member for holding the head in adjusted position,

Fig. 6 being taken on the line 66 of Fig. 1.

Figs. 8 and 9 are detail views of one preferred form of adjustment means for adjusting the 10 length of the arms, Fig. 8 being taken along the line 8-8 of Fig. 1, and Fig. 9 being a transverse section along the line 9-9 of Fig. 8.

Figs. 10 and 11 are side, sectional and top views respectively of a second preferred form of adjustment means.

Fig. 12 shows a third form of adjustment means, and

Figs. 13 and 14 are views illustrating a still further form of adjustment, particularly adapted for use with arms of the flat bar type, Fig. 14 being taken on the line 14-44 of Fig. 13.

Referring now to the drawings, and first to the embodiment of the invention illustrated in Figs.

1 to 9 inclusive, it will be seen that the parallel line or ruling apparatus illustrated comprises in general a bracket or holder ID by which the apparatus may be secured to a drawing board or the like It, a head construction indicated generally by the reference numeral l2 carrying the line ruling elements l3 and I4, and an operating mechanism or guiding means l5 operatively connecting the bracket and head.

' More specifically, see Fig. 2, the securing bracket l0 comprises an angle bracket member I6 5 adapted to be secured to one edge of the drawing board by suitable means such as screws 11. The bracket member is provided with a pair of upstanding lugs I8 which carry threaded pivot pins I9, the pins being secured in position by lock 40 nuts 20. .A plate member 2! is mounted for pivotal movement upon the pivot pins. This plate member carries an adjustable screw 22, the lower end of which is adapted to engage the bracketmember l6 when the plate 2| is rotated counterclockwise to the position shown in Fig/2Q By' rotating the screw 22, the position at which the plate will be held by the screw may be adjustably predetermined.

The plate 2| also carries a'pair of pivot connections 23 to which the parallel extending arms 26 .1, and 25 of the operating mechanism are secured at one of their ends. The opposite ends of the.

arms are secured by similar pivot connections-26 to a four-armed plate member 27. This plate member is in turn secured by pivot connections 28 with a second set of parallel extending arms 29 and 30 which are adapted to be secured to the head l2 by the pivot connections 3|. It will be seen that by means of the operating mechanism, the head I2 may be readily moved to any desired position upon the face of the drawing board, and during such movements will always be maintained in the same angular position to which it may have been adjusted so that all lines drawn or devices, such as triangles or the like, positioned by the ruling elements i 3 and I4 will be maintained in parallel relation. During the movements of the head the arms of the operating mechanism act as double parallelograms and constantly maintain the parallel positioning and relation of the parts.

As will be best seen by reference to Figs. 1, 2, 3, 8 and 9, the arms are in the form of elongated metal tubes flattened at their ends to receive the pivot connections. This tubular construction of the arms provides maximum strength and rigidity in the apparatus with a minimum of weight. Each of the arms 24 and 2a is provided with an adjustment means 32 specifically illustrated in Figs. 8 and 9, for adjusting the arm length. The adjusting mechanism here illustrated comprises a manually operable knurled knob 33 fixed upon a rotatable cylindrical member 3%, threadedly received within the ends of the tubular arms. One of the ends of the member 3 3 is provided with right-hand threads whereas the other end is provided with left-hand threads, so that as the member is rotated by the knurled knob in one direction or the other, the parts of the tubular arm in threaded engagement with the member will be drawn toward each other or separated depending upon the direction of rotation.' Lock nuts 36 are provided for locking the member 3 3 in any desired position of adjustment. By means of the adjustment mechanism thus provided, micrometer adjustments may be imparted to accurately control or adjust the length of the arms 24 and 29. In manufacturing and assembly of the parts, slight inaccuracies or discrepancies may result,.so that if no adjustment means were provided, the arms might not be of equal effective length and arranged in true parallel relation. The adjusting mechanism not only provides a means for initially adjusting the arms to insure.

true positioning, but also provides a ready means for compensating for inaccuracies which may result from wear. Obviously adjusting means may also be provided in the arms 25 and 30, if desired. Ordinarily, however, an adjustment mechanism in one of each pair of arms will suffice to insure equal arm length and accurate positioning of the parts.

In Figs. 10 and 11 an alternate form of adjusting means is illustrated. In this instance the tubular arm is so constructed that one part 38 thereof is'smaller than the other part 39, the two parts being arranged in telescoping relation. The end of the inner or smaller tubular member 38 is provided with a block 40 which threadedly carries an adjusting screw 4|. This adjusting screw projects through a longitudinal slot 42 provided in the outer tubular member 39, a washer member 43 being provided, if desired. When the screw 4| is loosened the two telescoping arm parts 38 and 39 may be arranged in the desired adjusted position, the screw 4| sliding within the slot 42 during adjustment. When the screw member 4| is tightened, the parts will be held in adjusted position.

the arms are of the flat bar type. In this in- I stance one arm part 45 carries a pair of screws 46 adapted to slide within a slot 41 provided in the other arm part 48. When the screws are loosened, the arm parts may be adjusted to any desired position, screws will be firmly held against unauthorized movement.

In Fig. 12 a still further' form of adjusting means is illustrated. In this form of construction the smaller tubular arm part 50 is telescopically received within the larger tubular part 5| A threaded sleeve 52 is fixed to the end of the part 5! and has threaded connection with a cylindrical chuck member 53. The extreme end of the tube 5i is provided with a plurality of longitudinally extending slots 54 whereby to provide a plurality of extensions 55, which extensions are adapted to be embraced by the gripping portion 56 of the chuck member. Preferably this gripping portion and the tube extensions are provided with cooperating tapered surfaces as indicated atill. When the chuck member is rotated so as to be threadedly moved to the right, 7

as seen in Fig. 12, the tubular parts 50 and Si of the arm will be released for relative longitudinal adjusting movement. After adjustment the chuck is rotated so as to be moved to the left. This causes the gripping portion 56 of the chuck to firmly embrace the extensions 55 of tubeii which are in turn moved into tight gripping engagement with tube 50 whereby to hold the parts in adjusted position.

The pivotal connections 23, 26, 28 and 3| are all preferably of similar construction, and are illustrated in detail in Fig. 4. As here shown, the pivotal connection comprises a spherically-shaped member 60 of hard metal suitably secured to the end of the arm 30. Preferably the member 56 is riveted to the armas indicated at 8i whereby to form a tight and permanent connection between the parts. The outer spherical surface of member 60 cooperates with a conical opening 52 provided in the plate member 21. A bolt or screw 63 has its head portion engaged against the upper surface of the plate 21 and its shank threadedly received within the spherical member Bil. A look nut 84 is provided for locking the bolt in position. In the operation of this pivot connection parts 60, 63 and 64 move as a unit with the arm 30, members 60 and 63 having sliding bearing engagement with the plate 21. Over long periods of service wear may occur resulting in looseness in the bearing surfaces. This looseness,'however, may be readily removed by loosening the lock nut 64, and tightening bolt 63 after which the lock nut 64 is again drawn up to hold the parts in adjusted position. The spherical surface of the member 6|] and the cooperating conical surface 62 of the plate 21 maintain proper bearing, contact in all positions of adjustment. By reason of this readily operable and eflicient adjustment mechanism, the pivotal connections may be kept permanently tight. Looseness which would otherwise result in inaccuracy in the ap-,

and upon tightening of the ments l3 and i4 are adapted to be angularly ad- 75 be locked in any position of adjustment.

arson-1o this end theruling elements are pmvided as extensions of a rotatable drafting plate 66. This latter plate carries a pair of washers 61 and 68, by means of screws 69. The non-rotatable plate member 65 is provided with an opening for the reception of washer 61, the annular edge 69 of the plate being received between the washers 61 and 68 for bearing engagement therewith. A knob construction consisting of upper and lower parts I0 and II held together by a central screw 12 is anchored to the plate 65 and to the washers 61 and 68 for rotatable movement therewith. To hold the plate 66 and the ruling elements l3 and It in any desired angular position to which they may be adjusted by knob 10, plate 65 carries a locking device consisting of a handie member 15 and a locking disk IS. The disk 16 has a shank 11 which projects through an opening in base plate 65 into threaded engagement with the handle member 15. The disk is cut away as indicated at 18 for the reception of the outer peripheral edge of washer 61. When the handle member 15 is rotated to locking position, the locking disk I6 is drawn upwardly to clamp washer 61 tightly against plate 65. Plate 66 secured to washer 61 is thus locked in adjusted position. When the handle member 15 is rotated to release position, the locking disk 16 is lowered slightly releasing washer 61 so that plate 66 may be adjusted by means of knob 10. As shown in Fig. 1, the base plate 65 carries a pair of gauge lines 80 which cooperate with a Vernier scale 8| secured to plate 66 by suitable means such as rivets 82. Plate 66 alsoparries a foot member 83 to facilitate smooth movement of the head construction over the face of the drawing board, the line ruling elements being bent downwardly as indicated at B4 to compensate for the height of the foot member. If desired, a similar foot member (not illustrated) may be provided on the plate member 2'|.'

It is obvious that various changes may be made in the specific embodiments set forth for purposes of illustration without departing from the spirit of the invention. The invention is accordingly not to be limited to the specific embodiments shown and described, but only as indicated in the following claims.

The invention is hereby claimed as follows:

1. A parallel line drafting apparatus comprising a holder adapted to be mounted upon a drafting board, a drafting head, an operating mechanism connecting the holder and head, said operating mechanism comprising a series of arms arranged in pairs, the arms of each pair being parallel for parallelogram operation, pivot connections for mounting said arms, one of said pivot connections comprising a spherical bearing mem-' ber mounted in the end of one of said arms, a cooperating bearing member having a conical opening adapted to be slidably engaged by the spherical surface of said spherical bearing member, and an adjustable clamping member adapted to directly engage both of said bearing members and adapted on adjustment to bring the bearing surfaces thereof into proper bearing engagement.

2. A parallel line drafting apparatus comprising a holder adapted to be mounted upon a drafting board, a drafting head, an operating mechanism connecting the holder and head, said operating mechanism comprising a series of arms arranged in pairs, the arms of each pair being parallel for parallelogram operation, pivot connections for mounting said arms, one of said pivot connections comprising a bearing member mounted in the end of one of said arms, a cooperating bearing member having an opening adapted to be slidably engaged by a surface of said firstnamed bearing member, and an adjustment screw adjustably secured to said first named bearing member and having a head porof said pivot connections comprising a bearing member mounted in the end of one of said arms,

a cooperating bearing member having an opening adapted to be engaged by a surface of said first named bearing member, and an adjusting screw threadedly secured to said first named bearing member and having a head portion adapted to engage said cooperating bearing member, whereby upon adjustment of said screw the bearing surfaces of said bearing members may be brought into proper contacting relation.

4. A parallel line drafting apparatus comprising a holder adapted to be mounted upon a drafting board, a drafting head, an operating mechanism connecting the holder and head, said operating mechanism comprising a series of arms, pivot connections for mounting said arms, one of said pivot connections comprising a bearing member mounted in the end of one of said arms, a cooperating bearing member having an opening adapted to be engaged by a surface of said first named bearing member, an adjusting screw threadedly secured to said first named bearing member and having a head portion adapted to engage said cooperating bearing member, whereby upon adjustment of said screw the bearing surfaces of said bearing members may be brought into proper contacting relation, and a lock hut also threadedly secured to said screw and adapted on threaded-movement to bear against said first named bearing member whereby to lock said adjusting screw in adlusted position. v

5. A parallel line drafting apparatus comprising a holder adapted to be mounted upon a drafting board, a drafting head, an operating mechanism connecting the holder and head, said operating mechanism comprising a series of arms arranged in pairs, the arms of each pair being partions for mounting said arms, one of said pivot connections comprising a spherical bearing member mounted in the end of one of said arms, a cooperating bearing member having a conical openallel for parallelogram operation, pivot connecing adapted-to be engaged by the spherical surface of said spherical bearing member, and an adjustment screw adjustably secured to the spherical bearing member and having a head portion adapted to engage said coop erating bearing member, whereby upon adjustment of said adjusting screw the bearing surfaces of said bearing members may be brought into proper contacting relation.

6. A parallel line drafting apparatus comprising a holder adapted to be mounted upon a drafting board, a drafting head, an operating mechanism for connecting the holder and head, said head comprising a base plate adapted to be secured to the operating mechanism, a drafting plate rotatably adjustable with respect thereto, and means for rotatably mounting said drafting plate upon the base plate, said mounting means comprising a pair of bearing plates secured to the drafting plate and adapted to have bearing engagement with the base plate, one of said bearing plates being adapted to have bearing engagement with one face of the base plate, and the other of said bearing plates having a flange adapted for bearing engagement on the other face of the base plate and a thickened body portion adapted to extend through an opening in the base plate in contact with the edge of said opening into engagement with the first bearing plate, and means for clamping said bearing plates together.

7. A parallel line drafting apparatus comprising a holder adapted to be mounted upon a drafting board, a drafting head, an operating mechanism for connecting the holder and head, said head comprising a base plate adapted to be secured to the operating mechanism, a drafting plate rotatably adjustable with respect thereto, and means for rotatably mounting'said drafting plate upon the base plate, said mounting means comprising a pair of bearing plates secured to the drafting plate and adapted to have bearing engagement with the base plate, one of said bearing plates beingadapted to have bearing engagement with one face of the base plate, and the other of said bearing plates having a flange plate upon the base adapted for bearing engagement on the other face of the base plate and a thickened body portion adapted to extend through an opening in the base plate in contact with the edge of said opening into engagement with the first bearing plate, a foot member secured to the drafting plate, and integral line ruling extensions formed on the drafting plate, said extensions being bent downwardly into the plane ofthe'supporting portion of the foot member;

8. A parallel line drafting apparatus comprising a holder adapted to be mounted upon a drafting board, a drafting head, anoperating mechanism for connecting the holder and head, said head comprising a base plate adapted to be secured to the operating mechanism, a drafting plate rotatably adjustable with respect thereto, and means for r'otat'ably mounting said drafting comprising apair of bearing plates secured to the drafting plate and adapted to have bearing engagement with the base plate, one of said bearing plate, said mounting means plates being adapted to have bearing engagement with one face of the base plate, the other of said bearing plates having a flange adapted for bearing engagement on the other face of the base plate and a thickened body portion adapted to extend through an opening in the base plate in contact with the edge of said opening into engagement with the first bearing plate, and a locking device mounted upon the base plate and adapted to be brought into clamping engage ment with one of said bearing plates.

ADOLPH LANGSNER. 

